grok-4-fast

completions

byopenrouter

grok-4-fast

completions

Published by: x-aiProvider:

openrouter

Grok 4 Fast is xAI's latest multimodal model with SOTA cost-efficiency and a 2M token context window. It comes in two flavors: non-reasoning and reasoning. Read more about the model on xAI's [news post](http://x.ai/news/grok-4-fast). Reasoning can be enabled using the `reasoning` `enabled` parameter in the API. [Learn more in our docs](https://openrouter.ai/docs/use-cases/reasoning-tokens#controlling-reasoning-tokens) Prompts and completions on Grok 4 Fast Free may be used by xAI or OpenRouter to improve future models.

Released

Aug 28, 2025

Knowledge

Mar 1, 2025

License

Proprietary

Context

Input

$0.2 / 1M tokens

Output

$0.5 / 1M tokens

Cached

$0.05 / 1M tokens

Capabilities: tools, reasoning

Accepts: text, image

Returns: text

Released Aug 28, 2025Knowledge Cutoff: Mar 1, 2025License: Proprietary

Context: 2M Input: $0.2 / 1M tokensOutput: $0.5 / 1M tokensCached: $0.05 / 1M tokensCapabilities: tools, reasoningAccepts: text, imageReturns: text

Access grok-4-fast through LangDB AI Gateway

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10,000+Monthly Requests

Benchmark Results for grok-4-fast

Category Performance Scores:

Maths: Score 89.70 (Top 9% - Rank #29)
Finance: Score 75.00 (Top 10% - Rank #32)
Science: Score 77.29 (Top 9% - Rank #29)
Writing: Score 64.45 (Top 15% - Rank #48)
Academia: Score 72.50 (Top 6% - Rank #20)
Marketing: Score 66.08 (Top 14% - Rank #45)
Programming: Score 48.40 (Top 13% - Rank #42)

Overall Performance: 70.48920634920634 average score across all categories

Detailed Benchmark Scores:

Benchmark	Score	Percentile	Domain
HLE	17.00	Top 10%	General Knowledge
GPQA	84.70	Top 3%	STEM (Physics, Chemistry, Biology)
SciCode	44.20	Top 3%	Scientific
MMLU-Pro	85.00	Top 8%	General Knowledge
LiveCodeBench	83.20	Top 6%	Programming
AA Math Index	89.70	Top 9%	Mathematics
AA Coding Index	48.40	Top 13%	Programming
AAII	60.30	Top 7%	General

GPQA Score: 84.70 - Graduate-level reasoning benchmark

Model Comparison:

Provider: openrouter

Model Type: completions

Context Size: 2000000 tokens

Comparing against 320 models in the database

Performance Analytics for grok-4-fast

Usage Statistics (Last 8 Days):

Total Requests: 400 API calls
Average TPS: 883.19 tokens per second
Average Response Time: 17505.40ms
Average Time to First Token: 15833.20ms
Total Cost: $1.90
Average Request Cost: $0.0048

Daily Performance Breakdown:

Date	Requests	TPS	Response Time	TTFT	Cost
11/11/2025	89	841.51	22532.30ms	22532.30ms	$0.53
11/12/2025	42	1219.96	21602.80ms	21066.40ms	$0.33
11/13/2025	58	659.37	14303.10ms	11425.90ms	$0.18
11/14/2025	24	1068.42	18805.20ms	17270.20ms	$0.15
11/15/2025	101	1054.02	9066.80ms	5797.30ms	$0.25
11/16/2025	35	814.21	22542.50ms	20689.50ms	$0.21
11/17/2025	48	702.12	21088.60ms	20097.70ms	$0.24
11/18/2025	3	461.28	30530.40ms	30530.40ms	$0.02

Performance Summary:

Model: grok-4-fast by openrouter

Monitoring Period: 11/11/2025 to 11/18/2025

Average Daily Requests: 50

Peak Daily Requests: 101

Statistics

View Full Statistics

Request Volume

Daily API requests

400

Performance (TPS)

Tokens per second

883.19 tokens/s

Category Scores

academia#10

Benchmark Tests

View Other Benchmarks

HLE

17.0

General Knowledge

GPQA

84.7

STEM (Physics, Chemistry, Biology)

SciCode

44.2

Scientific

MMLU-Pro

85.0

General Knowledge

LiveCodeBench

83.2

Programming

AA Math Index

89.7

Mathematics

AA Coding Index

48.4

Programming

AAII

60.3

General

Metric	HLE	GPQA	SciCode	MMLU-Pro	LiveCodeBench	AA Math Index	AA Coding Index	AAII
Score	17.0	84.7	44.2	85.0	83.2	89.7	48.4	60.3

Compare with Similar Models

Code Examples

Integration samples and API usage

Code Samples for grok-4-fast

Python SDK Example:

from openai import OpenAI

client = OpenAI(
    base_url="https://api.us-east-1.langdb.ai//projects/<your_project_id>",
    api_key="<your_api_key>"
)

response = client.chat.completions.create(
    model="grok-4-fast",
    messages=[
        {"role": "user", "content": "Hello, how are you?"}
    ]
)

print(response.choices[0].message.content)

TypeScript SDK Example:

import OpenAI from 'openai';

const client = new OpenAI({
    baseURL: "https://api.us-east-1.langdb.ai//projects/<your_project_id>",
    apiKey: "<your_api_key>"
});

const response = await client.chat.completions.create({
    model: "grok-4-fast",
    messages: [
        { role: "user", content: "Hello, how are you?" }
    ]
});

console.log(response.choices[0].message.content);

cURL Example:

curl -X POST "https://api.us-east-1.langdb.ai//projects/<your_project_id>/v1/chat/completions" \
  -H "Authorization: Bearer <your_api_key>" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "grok-4-fast",
    "messages": [
        {"role": "user", "content": "Hello, how are you?"}
    ]
  }'

Model: grok-4-fast

Provider: openrouter

API Endpoint: $https://api.us-east-1.langdb.ai/

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grok-4-fast by openrouter - AI Model Details, Pricing, and Performance Metrics

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Access grok-4-fast through LangDB AI Gateway

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